Examining Trajectories of Alcohol and Tobacco Use in Canadian Lesbian, Gay, Bisexual, Transgender, and Gender-Diverse Midlife and Older Adults with Canadian Longitudinal Study on Aging (CLSA) Data.

Lesbian, gay, bisexual (LGB) and transgender and gender-diverse (TGD) adults experience elevated alcohol and tobacco use relative to heterosexual and cisgender adults, yet longitudinal trajectories of these disparities in midlife and older adulthood remain underexplored. Using data from the first three waves of the Canadian Longitudinal Study on Aging (CLSA; N = 45,079), we examined trajectories of drinking frequency, binge drinking frequency, smoking frequency, and daily cigarette consumption among aging Canadian LGB and TGD adults compared to their heterosexual and cisgender counterparts. Linear and generalized linear mixed models showed minimal differences in alcohol and tobacco use trajectories between aging LGB and TGD adults and their heterosexual and cisgender peers. All groups showed similar patterns of declining alcohol use with age, following quadratic trajectories in which declines steepened with older ages. Cisgender women reported lower substance use across all outcomes compared to cisgender men; TGD people's patterns did not differ from those of cisgender men. Trajectories of alcohol and tobacco use frequency were not systematically different between LGB and TGD aging adults relative to their heterosexual and cisgender counterparts in midlife and older adulthood. These shared declines are consistent with age-related processes shaping substance use similarly across identity groups in midlife and older adulthood.